What is a DKIM record?
Domain Keys Identified Mail, or DKIM record, is a TXT DNS record that proves that the emails sent from the domain are legit. That happens through cryptographic authentication. The DNS administrator of a domain is able to set it. On the other side, the receiver could also use the DKIM record and make a DNS query for the domain to check the sender utilizing the information in the header.
You could view the public key inside the DKIM record that the receiver is going to use to check the message.
With a DKIM record, you sign the email, and you will have to add a DKIM signature header and also encrypt it. The sending server sings the emails with its private key. After that, the receivers have to unlock them with the public key. This process ensures that the message was not spoofed and could be trusted.
How does DKIM work?
The DNS administrator and owner of the domain, in charge of the DNS records, issues a cryptographic public key. It can be found inside a modified TXT record. Its main purpose is for the recipients to be able to verify the authenticity of the emails of the sender.
Each time an email is sent by a mails server, it includes a DKIM signature in the header of the email. The signature is represented with a hash value that is an individual textual string encrypted by a private key that is available only for the sender.
The header holds data about the way the signature was created, plus it carries two cryptographic hashes. One of them applies to the message body, and the other one belongs to the defined headers.
Once the receiver email server accepts an email, it triggers a DNS request. The goal is to locate the public key from the sender domain. The DKIM signature is the one offering information to discover that key successfully.
The sender email server is going to get and decrypt the DKIM signature from the email to its original hash values. If they match, DKIM is going to validate them as legit.
Benefits of using DKIM record
Easy enable of DKIM. It does not require three-party certification to operate because it is a self-certificate method.
It keeps your users safe from email forging. DKIM record protects the emails you send from its email server from being forged or modified during transit. DKIM is an excellent tool for your organization to develop a trustable image by preventing spoofing and phishing.
Emails bodies are not affected. The data for authenticating and verifying is included in the header.
It runs on domain names’ level. The DNS administrator is the one who signs all the outgoing emails. It is not necessary for every single user to do it whenever is sending a message.
Better security through DMARC. There are also other security mechanisms with which you are able to improve your guard potential, such as the DMARC record. In addition, having a DKIM record is the foundation for it to operate.